In such a case, parking costs will reduce. Since the number of cars are expected to be lower if they are driverless, the amount of space required for parking will be less. It would also mean that expenditure on the prime real estate required would be less (marginal costs are higher, marginal decrease would hence be more benefitial) and that will result in cheaper parking.

Secondly, it also opens up the scope for private taxies. A person can allow his car to be utilized by a certain section of his peers - colleagues, neighbours etc for low prices - resulting in lower parking time.